Ganga water pollution: A potential health threat to inhabitants of Ganga basin

Water quality assessment of Upper Ganga and Yamuna river systems during COVID-19 pandemic-induced lockdown: imprints of river rejuvenation

Clean river water is an essential and life-sustaining asset for all living organisms. The upper Ganga and Yamuna river system has shown signs of rejuvenation and tremendous improvement in the water quality following the nationwide lockdown due to the coronavirus pandemic. All the industrial and commercial activity was shut down, and there was negligible wastewater discharge from the industries. This article addresses the water quality assessment from the study area, which is based on the original data of physical parameters, major and trace elements, and stable isotopes (hydrogen and oxygen) systematics during the nationwide lockdown. The impact of the lockdown could be seen in terms of an increase in dissolved oxygen (DO). Water samples were collected from the Upper Ganga and Yamuna river basins (Alaknanda, Bhagirathi, and Tons rivers) during an eight-week lockdown in Uttarakhand, India. We discussed the signs of rejuvenation of riverine based on physical parameters, major ions, trace elements, isotopic ratios, and water pollution index (WPI). Results reveal that the water quality of the entire upper basins of the Ganga has significantly improved by 93%, reflecting the signs of self-rejuvenation of the rivers. Multivariate analysis suggests a negative factor loading for an anthropogenic element (NO 3 - ), implying that they contribute little to the river water during the lockdown. Further, bicarbonate (HCO 3 - ) is a dominant element in both river basins. The geochemical facies are mainly characterized by the (Ca 2 + : Mg 2 + : H C O 3 - ) type of water, suggesting that silicate rock weathering dominates with little influence from carbonate weathering in the area. The positive factor loadings of some cations, likeHCO 3 - ,Ca 2 + , andMg 2 + reflect their strong association with the source of origin in the lockdown phases. Stable isotopic reveals that the glaciated region contributed the most to the river basin, as evidenced by the low d-excess in riverine water compared to anthropogenic contributions. Rivers can self-rejuvenate if issues of human influence and anthropogenic activities are adequately resolved and underline our responsibility for purifying the ecosystem. We observed that this improvement in the river water quality will take a shorter time, and quality will deteriorate again when commercial and industrial activity resumes.

Organic matter sources and distribution along land-use gradient in a Himalayan foothills River: Insights from molecular markers

The analysis of hydrocarbon biomarkers in surface sediments along the Markanda River in the foothills of the Indian Himalayas was conducted to gain insights into the distribution and composition of organic matter (OM) within the sediments. This investigation is essential for comprehending how anthropogenic changes are influencing the OM dynamics in river systems. The study involved identification and quantification of various compound groups such as n-alkanes, hopanes, steranes, polycyclic aromatic hydrocarbons (PAHs), linear alkyl benzenes (LABs) and phthalate esters along with their respective parametric ratios. The variation in distribution of n-alkanes and associated indices (odd-even carbon number predominance (OEP), average chain length (ACL), terrigenous to aquatic ratio (TAR), carbon preference index (CPI), and natural n-alkanes ratio (NAR)) were used to distinguish the natural source of organic content from those influenced by anthropogenic contamination. The detection of petroleum contamination was indicated by the presence of prominent unresolved complex mixtures (UCM) as well as specific petroleum biomarkers such as hopanes, diasteranes, and steranes. The study revealed varying concentrations of the analyzed organic pollutants, with the average of PAHs at 24.6 ng/g dw, LABs at 18.1 ng/g dw, and phthalates at 8.3 μg/g dw. The variability in concentration of the investigated compound groups across different locations indicated spatial heterogeneity, and the land use patterns appears to modulate the sources of OM in surface sediments. The source contribution of PAHs and phthalates determined by positive matrix factorization (PMF) shows the predominant sources of the anthropogenic hydrocarbons were linked primarily to petroleum/petroleum-derived products emissions, industrial discharges, cultural practices and common household waste/sewage disposal. This analysis provides insights for developing mitigation strategies and informing relevant policy changes globally, thereby contributing to the broader understanding of anthropogenic impacts on water ecosystems.

A comprehensive assessment of macro and microplastics from Rivers Ganga and Yamuna: Unveiling the seasonal, spatial and risk factors

There have been growing apprehensions and concerns regarding the increasing presence of plastic pollutants in the holiest river of India, the Ganga, and its major tributary, Yamuna. In response to this issue, the current study aimed to conduct a comprehensive investigation of the seasonal and spatial distribution of macro to microplastics (MPs) in the surface water, water column, and sediments from the River Ganga and Yamuna. MP samples were collected from various points of these Rivers, including upstream, downstream, and drainage points around the vicinity of Haridwar, Agra, Prayagraj, and Patna cities. With a significant seasonal variation, the estimated MPs and plastic flux were higher during the wet season than during the dry season. MPs sized 300 µm-1 mm and fibre-shaped blue and black colored MPs were pre-dominant in both rivers. Polyacrylamide, polyamide, and polyvinyl chloride were the most ascertained polymers. MPs including hazardous polymers (hazard score >1000) may pose a risk to the population of Indo-Gangetic Plain via direct and indirect exposure to MPs. The information provided in this study could serve as a starting point for the action plan required by municipal corporations to mitigate plastic pollution and target the possible sources at each location.

Prognostic Insights and Survival Analysis of Gallbladder Cancer in Bihar, India: a Prospective Observational Study Emphasizing the Impact of Surgical Intervention on Overall Survival

The aim of this study was to determine the 1- and 3-year overall survival rates. This prospective observational study was conducted at a tertiary care center in Bihar state, India. The study analyzed 228 patients in Bihar with a median age at diagnosis of 55 ± 12.05 years. The most common symptoms included upper abdominal pain (26.3%), weight loss (14%), and ascites (13.6%). The majority of patients presented at stage IV (72.8%), with liver metastasis being prevalent (61.4%). Interventional biliary drainage was performed in 9.6% of cases, and systemic chemotherapy was received by 84.64%, while 15.36% opted for best supportive care. Univariate Cox regression analysis identified Eastern Cooperative Oncology Group (ECOG) performance status, stage, gallstone disease, and surgical intervention as significant risk factors influencing overall survival (OS) (p < 0.001). Multivariate Cox regression analysis confirmed ECOG performance status (p < 0.001), stage (p = 0.039), and surgical intervention (p = 0.038) as independent factors impacting OS. One-year OS rates for stages II, III, and IV were 100%, 97%, and 44%, respectively, while 3-year OS rates were 29%, 4%, and 0%. Surgical intervention significantly influenced OS (p < 0.001). OS for surgical intervention was 28 months, and for inoperable cases, it was 12 months. One- and 3-year OS for surgical intervention were 95% and 11%, while for inoperable cases, they were 41% and 0%, respectively. Patients with gallbladder cancer, particularly in Bihar's Gangetic plains, face poor survival, especially with advanced disease. Adequate surgery improves outcomes, prompting a call for enhanced strategies, particularly for locally advanced GBC.

Pesticides impacts on human health and the environment with their mechanisms of action and possible countermeasures

Pesticides are chemical constituents used to prevent or control pests, including insects, rodents, fungi, weeds, and other unwanted organisms. Despite their advantages in crop production and disease management, the use of pesticides poses significant hazards to the environment and public health. Pesticide elements have now perpetually entered our atmosphere and subsequently contaminated water, food, and soil, leading to health threats ranging from acute to chronic toxicities. Pesticides can cause acute toxicity if a high dose is inhaled, ingested, or comes into contact with the skin or eyes, while prolonged or recurrent exposure to pesticides leads to chronic toxicity. Pesticides produce different types of toxicity, for instance, neurotoxicity, mutagenicity, carcinogenicity, teratogenicity, and endocrine disruption. The toxicity of a pesticide formulation may depend on the specific active ingredient and the presence of synergistic or inert compounds that can enhance or modify its toxicity. Safety concerns are the need of the hour to control contemporary pesticide-induced health hazards. The effectiveness and implementation of the current legislature in providing ample protection for human health and the environment are key concerns. This review explored a comprehensive summary of pesticides regarding their updated impacts on human health and advanced safety concerns with legislation. Implementing regulations, proper training, and education can help mitigate the negative impacts of pesticide use and promote safer and more sustainable agricultural practices.

Artificial intelligence and machine learning algorithms in the detection of heavy metals in water and wastewater: Methodological and ethical challenges

Heavy metals (HMs) enter waterbodies through various means, which, when exceeding a threshold limit, cause toxic effects both on the environment and in humans upon entering their systems. Recent times have seen an increase in such HM influx incident rates. This requires an instant response in this regard to review the challenges in the available classical methods for HM detection and removal. As well as provide an opportunity to explore the applications of artificial intelligence (AI) and machine learning (ML) for the identification and further redemption of water and wastewater from the HMs. This review of research focuses on such applications in conjunction with the available in-silico models producing worldwide data for HM levels. Furthermore, the effect of HMs on various disease progressions has been provided, along with a brief account of prediction models analysing the health impact of HM intoxication. Also discussing the ethical and other challenges associated with the use of AI and ML in this field is the futuristic approach intended to follow, opening a wide scope of possibilities for improvement in wastewater treatment methodologies.

Enzymatic and transcriptional level changes induced by the co-presence of lead and procymidone in hook snout carp (Opsariichthys bidens)

Understanding the interactions between different environmental pollutants is necessary in ecotoxicology since environmental contaminants never appear as single components but rather in combination with other substances. Heavy metals and pesticides are commonly detected in the environment, but the characterization of their mixture toxicity has been inadequately explored. This research aimed to elucidate the mixture impacts of the heavy metal lead (Pb) and the pesticide procymidone (PCM) on the hook snout carp (Opsariichthys bidens) using an array of biomarkers. The data showed that Pb and PCM possessed almost equivalent acute toxicity to the animals, with 4-days LC50 values of 120.9 and 85.15 mg L-1, respectively. Combinations of Pb and PCM generated acute synergistic effects on O. bidens. The contents of malondialdehyde (MDA), antioxidative (SOD), apoptotic (caspase-9), and detoxifying enzymes glutathione S-transferase (GST) and cytochrome P450 (CYP450) significantly changed after most of the mixture exposures compared with the baseline level and the corresponding individual exposures. This suggests the induction of oxidative stress, cell damage, and detoxification dysfunction. The expressions of eight genes (mn-sod, cu-sod, p53, cas3, erβ1, esr, ap, and klf2α) associated with oxidative stress, cell apoptosis, immune response, and hormonal functions exhibited pronounced changes when challenged with the mixture compared to the individual treatments. This indicates the occurrence of immune dysregulation and endocrine disorder. These findings provide an overall understanding of fish upon the challenge of sublethal toxicity between Pb and PCM and can be adopted to evaluate the complicated toxic mechanisms in aquatic vertebrates when exposed to heavy metal and pesticide mixtures. Additionally, these results might guide environmental regulation tactics to protect the population of aquatic vertebrates in natural ecosystems.

Alteration of haematological and biochemical biomarkers after sub-lethal chronic malathion (Elathion®) intoxication in freshwater fish, Labeo rohita (Hamilton, 1822)

The present investigation aimed to evaluate the long-term effects of malathion (Elathion®) at two sub-lethal concentrations (0.36 and 1.84 mgL-1) for 45 days after the determination of 96 h-LC50 value (18.35 mgL-1) in a commercially important aquaculture species, Labeo rohita by assaying multiple biomarker approaches. Total erythrocyte count (TEC), and haemoglobulin count (Hb) were found to be decreased while total leucocyte counts (TLC) were increased (p < 0.05) in malathion-intoxicated fish. Malathion exposure significantly reduced (p < 0.05) serum protein levels while significantly increased (p < 0.05) blood glucose levels. RNA activity in muscle was reduced (p < 0.05) while DNA activity increased (p < 0.05) in malathion-intoxicated fish. Acid phosphatase (ACP) activities in the brain; lacate dehydrogenase (LDH) activities in brain and liver were increased (p < 0.05), while alkaline phosphatase (ALP) activities in the brain; succinate dehydrogenase (SDH) activities in the brain, liver and kidney; acetylcholine esterase (AChE) activity in the brain; and ATPase activities in the brain, liver and kidney were reduced (p < 0.05) in comparison to control. Thus, the alteration in studied biomarkers was in a concentation-time dependent manner; however, it was more pronounced at the higher concentration at 45 days of exposure. The alteration in biomarker activity is probably a defensive mechanism/ adaptive response of fish to overcome the stress induced by malathion, which is a novel insight and possible impact on L.rohita. Our findings suggest malathion-induced stress, therefore, the use of malathion needs to be regulated to safeguard aquatic animals including fish and human health.

Efficient photocatalytic degradation of textile dye pollutants using thermally exfoliated graphitic carbon nitride (TE-g-C3N4)

Graphitic carbon nitride (g-C3N4), an organic photocatalyst was reported to have beneficial properties to be used in wastewater treatment applications. However, g-C3N4, in its bulk form was found to have poor photocatalytic degradation efficiency due to its inherent limitations such as poor specific surface area and fast electron-hole pair recombination rate. In this study, we have tuned the physiochemical properties of bulk g-C3N4 by direct thermal exfoliation (TE-g-C3N4) and examined their photocatalytic degradation efficiency against abundant textile dyes such as methylene blue (MB), methyl orange (MO), and rhodamine B (RhB). The degradation efficiencies for MB, MO, and RhB dyes are 92 ± 0.18%, 93 ± 0.31%, and 95 ± 0.4% respectively in 60 min of UV light irradiation. The degradation efficiency increased with an increase in the exfoliation temperature. The prepared catalysts were characterized using FTIR, XRD, FE-SEM, EDAX, BET, and UV-DRS. In BET analysis, TE-g-C3N4 samples showed improved surface area (48.20 m2/g) when compared to the bulk g-C3N4 (5.03 m2/g). Further, the TE-g-C3N4 had 2.98 times higher adsorption efficiency than the bulk ones. The free radicals scavenging studies revealed that the superoxide radicals played an important role in the photodegradation for dyes, when compared to the hydroxyl radical (.OH) and the photo-induced holes (h+), Photoluminescence (PL) emission and electrochemical impedance spectroscopy (EIS) spectra of TE-g-C3N4 indicated a lowered electron-hole pairs' recombination rate and an increased photo-induced charge transfer respectively. Further, the TE-g-C3N4 were found to have excellent stability for up to 5 cycles with only a minor decrease in the activity from 92% to 86.2%. These findings proved that TE-g-C3N4 was an excellent photocatalyst for the removal and degradation of textile dyes from wastewater.

Cascading effects of trace metals enrichment on phytoplankton communities of the River Ganga in South Asia

Globally freshwater ecosystems and associated biota including phytoplankton communities are at extreme risk from trace metal pollution originating from geogenic as well as from anthropogenic sources such as release of untreated industrial effluents. In the present study influence of iron- and arsenic-enrichments on structure and metabolism of phytoplankton communities of River Ganga, one of the largest rivers of South Asia, was assessed under laboratory-based microcosm experiments. Surface water samples were collected and subsequently enriched with higher than recommended concentrations of iron (10 mg/L) and arsenic (10 μg/L). The set-up comprised of nine containers of 25 L volume with three containers each for iron- and arsenic-enrichment and was maintained for 30 days. Trace metal enrichment rapidly changed the phytoplankton community structure and chemistry of nutrients uptake. Iron-enrichment prompted diatom blooms comprising of Thalassiosira, succeeded by green algae Coelastrum. Arsenic-enrichment maintained cyanobacteria for longer time-spans compared to the control and iron-enriched containers but significantly lesser abundance of diatoms. Variations in community composition was also reflected in nutrient uptake rates with silicate release in the arsenic-enriched containers at the end of the experiment. Changes in macronutrient dynamics also altered genus growth rates wherein both iron- and arsenic appeared to lower the death rate of Thalassosira but stimulated growth of other genera including Skeletonema and Pandorina. Iron appeared to influence lesser number of genera compared to arsenic which altered growth rates of both diatoms and green algae. This consequently influenced the gross primary productivity values which lowered both in the iron- and arsenic-enriched containers compared to the control owing to decrease in phytoplankton diversity. Iron appeared to drive phytoplankton communities toward a less general and more specialized composition with high abundance of selective species comprising of small diatoms such as Thalassiosira, whereas arsenic appears to select for green algal enrichment in freshwater ecosystems.

Abundance, characterization, and removal of microplastics in different technology-based sewage treatment plants discharging into the middle stretch of the Ganga River, India

Sewage treatment plants (STPs) are considered as a prominent source for releasing microplastics (MPs) into the riverine systems. Though MPs abundance and removal efficacy in different secondary treatment technique-based STPs have been extensively studied worldwide, such studies are scarce in Indian conditions. Herein, this study comprehensively assesses MPs abundance, characterization, and their removal in the selected secondary treatment technique-based STPs discharging into the middle stretch of the Ganga River in India. MPs concentration (n/L) in influent and effluent of the STPs varied between 42 ± 10 to 150 ± 19 and 3 ± 1 to 22 ± 5, respectively. Overall, the primary treatment stage was observed to remove MPs by 23-42 %, while the secondary treatment stage removed MPs by 67-90 %. Selected technique-based STPs exhibited varying MPs removal efficacies as follows: SBR (94 %), TF (90 %), AL (88 %), UASB (87 %), ASP (85 %), FAB (84 %), and Bio-tower (77 %). MPs ranging from 50 to 250 μm were the dominant sizes, with PP, PE, and PS being the prevalent polymers. The Ganga River receives about 3 × 108 MPs/day from STP effluents, and an estimated 4.5 × 107 MPs/day are released via the sludge. This comprehensive assessment of MPs abundance and removal from different technology-based Indian STPs will allow the comparison of the generated dataset with similar studies worldwide.

Early detection of emerging persistent perfluorinated alkyl substances (PFAS) along the east coast of India

Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonate (PFOS) are resistant to breakdown and are now considered global contaminants. However, interest in these recalcitrant compounds among scientists and legislators has grown significantly in recent years. In the present study, we analyzed the level of PFOA and PFOS contamination in surface water from the coastal regions of Tamil Nadu and West Bengal. After solid phase extraction, 49 samples were analyzed by liquid chromatography coupled with mass spectrometry (LOD ≤ 1.5 ng L-1). The PFOA and PFOS present in all samples at the highest concentration were found in the Ennore coastal region (reaching a maximum of 24.8 ng L-1 and 13.9 ng L-1 in CH-6 and CH-14 respectively). Similarly, on the West Bengal coast, concentrations of PFOA ranged from <1.5 to 14.0 ng L-1 and <1.3 to 8.2 ng g-1 in water and sediment respectively. PFOS concentrations in water and sediment ranged from <1.2 to 9.0 ng L-1 and <1.2 to 7.9 ng g-1, respectively. According to the principal component analysis, the majority of the variances (65.04 %) show a positive association, which points to industrial and domestic discharges as significant point sources of these compounds. The results from this study could be used to determine and understand the levels of PFOA and PFOS contamination along the Indian Coast as well as provide baseline information for imminent monitoring investigations. The environmental occurrences of PFOA and PFOS reported in the current study would allow policymakers to take appropriate measures to safeguard coastal ecosystems or reduce the likelihood of contamination, creating a sustainable and healthy environment.

Healthy Drinking Water as a Necessity in Developing Countries Like India: A Narrative review

Water is an indispensable part of human life. This article is an extensive review that focuses on the importance of water to sustain human life, the necessity of healthy, safe drinking water, and the health hazards of drinking untreated and contaminated water. We drink treated water thinking it to be safe without the knowledge that it, too, has harmful effects. Detrimental health effects due to water chlorination are mentioned in this article. The usage of nanoparticles for the treatment of water is an alternative to chlorination, but they are little in use as they are expensive. Transmission of waterborne diseases through drinking water is widespread in a developing country like India. A list of the pathogens contaminating drinking water is present in the review. Pathogens pollute water, and heavy metals and chemicals from industries, pesticides, pharmaceutical compounds, and radioactive waste also taint it. The harmful effects of metal and chemical toxicities on human health are discussed in this review. The government of India has launched several programmes to ensure clean, safe drinking water for all its residents. The study reflects on the treatment given to individuals suffering from waterborne diseases in India. Significant changes in health status in India have been seen recently after the execution of various government programmes to provide safe, healthy drinking water to all its residents.

Geochemical evolution of dissolved trace elements in space and time in the Ramganga River, India

Understanding the spatiotemporal dynamics of river water chemistry from its source to sinks is critical for constraining the origin, transformation, and "hotspots" of contaminants in a river basin. To provide new spatiotemporal constraints on river chemistry, dissolved trace element concentrations were measured at 17 targeted locations across the Ramganga River catchment. River water samples were collected across three seasons: pre-monsoon, monsoon, and post-monsoon between 2019 and 2021. To remove the dependency of trace element concentrations on discharge, we used molar ratios, as discharge data on Indian transboundary rivers are not publicly available. The dataset reveals significant spatiotemporal variability in dissolved trace element concentrations of the Ramganga River. Samples collected upstream of Moradabad, a major industrial city in western Uttar Pradesh, are characterized by ~ 1.2-2.5 times higher average concentrations of most of the trace elements except Sc, V, Cr, Rb, and Pb, likely due to intense water-rock interactions in the headwaters. Such kind of enrichment in trace metal concentrations was also observed at sites downstream of large cities and industrial centers. However, such enrichment was not enough to bring a major change in the River Ganga chemistry, as the signals got diluted downstream of the Ramganga-Ganga confluence. The average river water composition of the Ramganga River was comparable to worldwide river water composition, albeit a few sites were characterized by very high concentrations of dissolved trace elements. Finally, we provide an outlook that calls for an assessment of stable non-traditional isotopes that are ideally suited to track the origin and transformation of elements such as Li, Mg, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Sr, Ag, Cd, Sn, Pt, and Hg in Indian rivers.

Therapeutic targeting of microtubule affinity-regulating kinase 4 in cancer and neurodegenerative diseases

Microtubule affinity-regulating kinase 4 (MARK4) is a member of the Ser/Thr protein kinase family, phosphorylates the microtubule-connected proteins and plays a vital role in causing cancers and neurodegenerative diseases. This kinase modulates multiple signaling pathways, including mammalian target of rapamycin, nuclear factor-κB, and Hippo-signaling, presumably responsible for cancer and Alzheimer's. MARK4 acts as a negative controller of the Hippo-kinase cassette for promoting YAP/TAZ action, and the loss of MARK4 detains the tumorigenic properties of cancer cells. MARK4 is involved in tau hyperphosphorylation that consequently affects neurodegeneration. MARK4 is a promising drug target for cancer, diabetes, and Alzheimer's. Developing the potent and selective inhibitors of MAKR4 are promising in the therapeutic management of associated diseases. Despite its great significance, a few reviews are available to discuss its structure, function and clinical significance. In the current review, we aimed to provide detailed information on the structural features of MARK4 targeted in drug development and its role in various signaling pathways related to cancer and neurodegenerative diseases. We further described the therapeutic potential of MARK4 inhibitors in preventing numerous diseases. Finally, the updated information on MARK4 will be helpful in the further development of effective therapeutic molecules.

Pesticide pestilence: Global scenario and recent advances in detection and degradation methods

Increased anthropogenic activities are confronted as the main cause for rising environmental and health concerns globally, presenting an indisputable threat to both environment and human well-being. Modern-day industrialization has given rise to a cascade of concurrent environmental and health challenges. The global human population is growing at an alarming rate, posing tremendous pressure on future food security, and healthy and environmentally sustainable diets for all. To feed all, the global food production needs to increase by 50% by 2050, but this increase has to occur from the limited arable land, and under the present-day climate variabilities. Pesticides have become an integral component of contemporary agricultural system, safeguarding crops from pests and diseases and their use must be reduce to fulfill the SDG (Sustainable Development Goals) agenda . However, their indiscriminate use, lengthy half-lives, and high persistence in soil and aquatic ecosystems have impacted global sustainability, overshot the planetary boundaries and damaged the pure sources of life with severe and negative impacts on environmental and human health. Here in this review, we have provided an overview of the background of pesticide use and pollution status and action strategies of top pesticide-using nations. Additionally, we have summarized biosensor-based methodologies for the rapid detection of pesticide residue. Finally, omics-based approaches and their role in pesticide mitigation and sustainable development have been discussed qualitatively. The main aim of this review is to provide the scientific facts for pesticide management and application and to provide a clean, green, and sustainable environment for future generations.

Emerging organic contaminants in the River Ganga and key tributaries in the middle Gangetic Plain, India: Characterization, distribution & controls

The presence and distribution of emerging organic contaminants (EOCs) in freshwater environments is a key issue in India and globally, particularly due to ecotoxicological and potential antimicrobial resistance concerns. Here we have investigated the composition and spatial distribution of EOCs in surface water along a ∼500 km segment of the iconic River Ganges (Ganga) and key tributaries in the middle Gangetic Plain of Northern India. Using a broad screening approach, in 11 surface water samples, we identified 51 EOCs, comprising of pharmaceuticals, agrochemicals, lifestyle and industrial chemicals. Whilst the majority of EOCs detected were a mixture of pharmaceuticals and agrochemicals, lifestyle chemicals (and particularly sucralose) occurred at the highest concentrations. Ten of the EOCs detected are priority compounds (e.g. sulfamethoxazole, diuron, atrazine, chlorpyrifos, perfluorooctane sulfonate (PFOS), perfluorobutane sulfonate, thiamethoxam, imidacloprid, clothianidin and diclofenac). In almost 50% of water samples, sulfamethoxazole concentrations exceeded predicted no-effect concentrations (PNECs) for ecological toxicity. A significant downstream reduction in EOCs was observed along the River Ganga between Varanasi (Uttar Pradesh) and Begusarai (Bihar), likely reflecting dilution effects associated with three major tributaries, all with considerably lower EOC concentrations than the main Ganga channel. Sorption and/or redox controls were observed for some compounds (e.g. clopidol), as well as a relatively high degree of mixing of EOCs within the river. We discuss the environmental relevance of the persistence of several parent compounds (notably atrazine, carbamazepine, metribuzin and fipronil) and associated transformation products. Associations between EOCs and other hydrochemical parameters including excitation emission matrix (EEM) fluorescence indicated positive, significant, and compound-specific correlations between EOCs and tryptophan-, fulvic- and humic-like fluorescence. This study expands the baseline characterization of EOCs in Indian surface water and contributes to an improved understanding of the potential sources and controls on EOC distribution in the River Ganga and other large river systems.

A review on degradation of organic dyes by using metal oxide semiconductors

The discharge of organic dye pollutants in natural water bodies has put forward a big challenge of providing clean water to a large part of the population. As the population is increasing with time, only underground water is not sufficient to complete the water requirements of everyone everywhere. Purification of wastewater and its reuse is the only way to fulfill the water needs. Nanotechnology has been used very efficiently for wastewater treatment via photocatalytic degradation of dye molecules. In the past few years, a lot of investigations have been done to enhance the photocatalytic activity of metal oxide semiconductors for water purification. In this review, we have discussed the different methods of synthesis of various metal oxide semiconductor nanoparticles, energy band gap, their role as efficient photocatalysts, radiations used for photocatalytic reactions, and their degradation efficiency to degrade the dye pollutants. We have also discussed the nanocomposites of metal oxide with graphene. These nanocomposites have been utilized as the efficient photocatalyst due to unique characteristics of graphene such as extended range of light absorption, separation of charges, and high capacity of adsorption of the dye pollutants.

A review on simultaneous heavy metal removal and organo-contaminants degradation by potential microbes: Current findings and future outlook

Industrial processes result in the production of heavy metals, dyes, pesticides, polyaromatic hydrocarbons (PAHs), pharmaceuticals, micropollutants, and PFAS (per- and polyfluorinated substances). Heavy metals are currently a significant problem in drinking water and other natural water bodies, including soil, which has an adverse impact on the environment as a whole. The heavy metal is highly poisonous, carcinogenic, mutagenic, and teratogenic to humans as well as other animals. Multiple polluted sites, including terrestrial and aquatic ecosystems, have been observed to co-occur with heavy metals and organo-pollutants. Pesticides and heavy metals can be degraded and removed concurrently from various metals and pesticide-contaminated matrixes due to microbial processes that include a variety of bacteria, both aerobic and anaerobic, as well as fungi. Numerous studies have examined the removal of heavy metals and organic-pollutants from different types of systems, but none of them have addressed the removal of these co-occurring heavy metals and organic pollutants and the use of microbes to do so. Therefore, the main focus of this review is on the recent developments in the concurrent microbial degradation of organo-pollutants and heavy metal removal. The limitations related to the simultaneous removal and degradation of heavy metals and organo-pollutant pollutants have also been taken into account.

Urbanization led to the abundance of Gram-negative, chemo-organo-heterotrophs, and antibiotic resistance genes in the downstream regions of the Ganga River water of India

The present investigation assesses the bacterial microbiome and antibiotic resistance genes (ARGs) of the river Ganga from Uttarakhand (upstream region; US group) and Uttar Pradesh (downstream region; DS group) regions using a 16S rRNA amplicon-based metagenomic approach. Gram-negative, aerobic, and chemo-organotrophic bacteria made up the majority of the bacterial genera during the overall analysis. Physicochemical analysis revealed a higher concentration of nitrate and phosphate in the downstream sites of the Ganga River. The prevalence of Gemmatimonas, Flavobacterium, Arenimonas, and Verrucomicrobia in the water of the DS region indicates a high organic load. Pseudomonas and Flavobacterium emerged as the most prevalent genera among the 35 significantly different shared genera (p-value < 0.05) in the US and DS regions, respectively. Overall antibiotic resistance analysis of the samples showed the dominance of β-lactam resistance (33.92%) followed by CAMP (cationic antimicrobial peptide) resistance (27.75%), and multidrug resistance (19.17%), vancomycin resistance (17.84%), and tetracycline resistance (0.77%). While comparing, the DS group exhibited a higher abundance of ARGs over the US group, where the CAMP resistance and β-lactam ARGs were dominant in the respective regions. The correlation (p-value < 0.05) analysis showed that most bacteria exhibit a significant correlation with tetracycline resistance followed by the phenicol antibiotic. The present findings draw attention to the need for regulated disposal of multiform human-derived wastes into the Ganga River to reduce the irrepressible ARGs dissemination.

Evaluating the efficacy and feasibility of post harvest methods for arsenic removal from rice grain and reduction of arsenic induced cancer risk from rice-based diet

Food-chain arsenic (As) contamination is a severe environmental and health problem worldwide, and its intake through rice affects billions of people. In this review, we have summarized the post harvest As removal methods from rice and their efficacy and feasibility. Rice grain subspecies (indica and japonica), size (short, medium and long), type (husked, parboiled or polished), soaking time, temperature and rice to water ratio (r/w) during washing and cooking are the major factors that affect the removal of total arsenic (tAs) from rice grain. The reduction in tAs was greater in japonica than indica rice and was directly proportional to As in husked rice. For the removal of As, a low water volume (1:2 r/w) was more effective during washing due to friction between rice grains, while high water (≥4 times water) during cooking was more effective. Up to 80 % As was removed by cooking in 1:10 (rice: water). Soaking rice in edible acids such as vinegar, acetic and ascorbic acid was not effective, except citric acid, which removes tAs up to 63 %. Human-health risk assessment showed that these post harvest and cooking methods reduce the non-carcinogenic and incremental lifetime cancer risk by up to 5-fold, as calculated on the basis of bioaccessible inorganic As. These post harvest methods also remove nutrient elements and vitamins. The recommended dietary intake (RDI) of Zn and Cu was particularly affected (up to 40 and 83 %). The levels of P, Mo, Mn and Co were still sufficient to meet the RDI through the rice-based diet, while rice is already poor in the RDI of Ca, K, Fe and Se, and their levels were further reduced by 0.22-44 %. In conclusion, these post harvest and cooking methods may significantly reduce As induced health risks; however, other dietary sources of nutrients need to be carefully evaluated and supplemented.

Microplastic pollution in the Himalayas: Occurrence, distribution, accumulation and environmental impacts

Microplastics have been reported from various ecosystems including lakes, ponds, wetlands, mountains, and forests globally. Recent research works showed microplastic deposition and accumulation in the Himalayan mountains and adjoining ecosystems, rivers and streams. Fine particles of microplastic originating from different anthropogenic sources can travel long distances, even upwards (altitudinally) through atmospheric transport and can pollute remote and pristine locations situated in the Himalayas. Precipitation also plays a vital role in influencing deposition and fallout of microplastics in the Himalayas. Microplastics can be trapped in the snow in glaciers for a long time and can be released into freshwater rivers by snow melting. Microplastic pollution in Himalayan rivers such as the Ganga, Indus, Brahmaputra, Alaknanda, and Kosi has been researched on both the upper and lower catchments. Additionally, Himalayan region draws many domestic and international tourists throughout the year, resulting in generation of massive and unmanageable volume of plastics wastes and finally ending up in the open landscapes covering forests, river streams and valley. Fragmentation of these plastic wastes can lead to microplastic formation and accumulation in the Himalayas. This paper discusses and explains occurrence and distribution of microplastics in the Himalayan landscapes, possible adverse effects of microplastic on local ecosystems and human population and policy intervention needed to mitigate microplastic pollution in the Himalayas. A knowledge gap was noticed regarding the fate of microplastics in the freshwater ecosystems and their control mechanisms in the Indian Himalayas. Regulatory approaches for microplastics management in the Himalayas sit within the broader plastics/solid waste management and can be implemented effectively by following integrated approaches.

Evolution of neural network to deep learning in prediction of air, water pollution and its Indian context

The scenario of developed and developing countries nowadays is disturbed due to modern living style which affects environment, wildlife and natural habitat. Environmental quality has become or is a subject of major concern as it is responsible for health hazard of mankind and animals. Measurements and prediction of hazardous parameters in different fields of environment is a recent research topic for safety and betterment of people as well as nature. Pollution in nature is an after-effect of civilization. To combat the damage already happened, some processes should be evolved for measurement and prediction of pollution in various fields. Researchers of all over the world are active to find out ways of predicting such hazard. In this paper, application of neural network and deep learning algorithms is chosen for air pollution and water pollution cases. The purpose of this review is to reveal how family of neural network algorithms has applied on these two pollution parameters. In this paper, importance is given on algorithm, and datasets used for air and water pollution as well as the predicted parameters have also been noted for ease of future development. One major concern of this paper is Indian context of air and water pollution research, and the research potential presents in this area using Indian dataset. Another aspect for including both air and water pollutions in one review paper is to generate an idea of artificial neural network and deep learning techniques which can be cross applicable for future purpose.

An integrated supervision framework to safeguard the urban river water quality supported by ICT and models

Models and information and communication technology (ICT) can assist in the effective supervision of urban receiving water bodies and drainage systems. Single model-based decision tools, e.g., water quality models and the pollution source identification (PSI) method, have been widely reported in this field. However, a systematic pathway for environmental decision support system (EDSS) construction by integrating advanced single techniques has rarely been reported, impeding engineering applications. This paper presents an integrated supervision framework (UrbanWQEWIS) involving monitoring-early warning-source identification-emergency disposal to safeguard the urban water quality, where the data, model, equipment and knowledge are smoothly and logically linked. The generic architecture, all-in-one equipment and three key model components are introduced. A pilot EDSS is developed and deployed in the Maozhou River, China, with the assistance of environmental Internet of Things (IoT) technology. These key model components are successfully validated via in situ monitoring data and dye tracing experiments. In particular, fluorescence fingerprint-based qualitative PSI and Bayesian-based quantitative PSI methods are effectively coupled, which can largely reduce system costs and enhance flexibility. The presented supervision framework delivers a state-of-the-art management tool in the digital water era. The proposed technical pathway of EDSS development provides a valuable reference for other regions.

A holistic review on trend, occurrence, factors affecting pesticide concentration, and ecological risk assessment

Demographic outbursts and increased food demands invoke excessive use of pesticides in the agricultural field for increasing productivity which leads to the relentless decline of riverine health and its tributaries. These tributaries are connected to a plethora of point and non-point sources that transport pollutants including pesticides into the Ganga river's mainstream. Simultaneous climate change and lack of rainfall significantly increase pesticide concentration in the soil and water matrix of the river basin. This paper is intended to review the paradigm shift of pesticide pollution in the last few decades in the river Ganga and its tributaries. Along with this, a comprehensive review suggests the ecological risk assessment method which facilitates policy development, sustainable riverine ecosystem management, and decision-making. Before 2011, the total mixture of Hexachlorocyclohexane was found at 0.004-0.026 ng/mL in Hooghly, but now, the concentration has increased up to 0.465-4.132 ng/mL. Aftermath of critical review, we observed maximum residual commodities and pesticide contamination reported in Uttar Pradesh > West Bengal > Bihar > Uttara Khand possibly because of agricultural load, increasing settlement, and incompetency of sewage treatment plant in the reclamation of pesticide contamination.

Exploring the impacts of physicochemical characteristics and heavy metals fractions on bacterial communities in four rivers

Heavy metals contamination in sediment poses serious threats to bacterial communities that play critical roles in sediment biogeochemical processes. However, the physicochemical factors and the major heavy metals fractions that affect sediment bacterial communities are still unclear. Here, we performed heatmap and redundancy analyses to examine the effects of physico-chemical characteristics and heavy metals fractions on the sediment bacterial community from rivers in the UK (River Tyne and Ouseburn) and India (River Ganga and Yamuna). The results revealed that physicochemical characteristics and heavy metals fractions altered the diversity, richness, and structures of the bacterial community. Moreover, the fractions of Co, Zn, Pb, Cr, and Cu played significant roles in shaping the bacterial community structure, and physicochemical variables, particularly NH₄⁺-N and NO₂^--N, also influenced the bacterial diversity and structure. Firmicutes showed strong associations with both physicochemical factors and heavy metals fractions. Chloroflexi and Actinobacteriota can be used as biomarkers for Zn contamination. Overall, our study identified the significance of sediment chemical characteristics and heavy metals fractions in determining the bacterial community structure as well as bioremediation and environmental management of metals contaminated sites.

Ganga River sediments of India predominate with aerobic and chemo-heterotrophic bacteria majorly engaged in the degradation of xenobiotic compounds

Sediment provides a stagnant habitat to microbes that accumulate organic matter and other industrial pollutants from the upper layer of the water. The sediment of the Ganga River of India is overlooked for exploring the bacterial diversity despite their taxon richness over the water counterpart. To enrich the limited information on the bacterial diversity of the Ganga River sediment, the present study was planned that relies on amplicon-based bacterial diversity of the Ganga River sediment by using bacterial-specific 16S hypervariable region (V₃-V₄). The Illumina MiSeq2500 platform generated 1,769,226 raw reads from the metagenomes of various samples obtained from ten sites in five major cities of Uttar Pradesh and Uttarakhand regions traversing the Ganga River. Taxonomy level analysis assigned 58 phyla, 366 order, and 715 genera of bacterial type. The high values of various diversity indices (Chao1, Shannon, and Simpson) in Kanpur sediment indicate the high bacterial richness compared to the Rishikesh sediment. However, several other ecological parameters (Shannon index, Simpson index, enspie _vector, and Faith_pd) were comparatively higher in Rishikesh sediment which is a comparatively less disturbed region by human activities over the other sediments samples studied here. Ganga River sediment dominates with Gram-negative, chemo-heterotrophic, and aerobic bacteria that chiefly belong to Proteobacteria, Acidobacteria, Chloroflexi, and Bacteroidota. The abundance of Nitrospira, Hydrogenophaga, Thauera, Vicinamibacteraceae, and Latescibacterota in the Ganga River sediment could be considered as the ecological indicators that find a significant role in the degradation of xenobiotic compounds. The PICRUSt-based analysis showed that ~ 35% of genes were involved in benzoate and aminobenzoate degradation where a significant portion of genes belong to nitrotoluene degradation (14%). Thus, the study uncovers a new perspective in the lineage of bacterial communities and their functional characterization of the Ganga River sediment.

Survival analysis and prognostic factors of the carcinoma of gallbladder

BACKGROUND

The present study aims to evaluate the survival status of patients with gallbladder cancer (GBC) and explore the prognostic factors for the improvement and preventions.

METHODS

The study consists of 176 patients with clinically diagnosed gallbladder cancer; the study was conducted between 2019 and 2021 registered at Kamala Nehru Memorial Cancer Hospital, Prayagraj, India. The survival rates were analyzed by the Kaplan-Meier method; survival rate difference was analyzed by log-rank test, prognosis factors; and hazard ratio for mortality outcomes was estimated using Cox regression method.

RESULTS

The overall median survival time of patients was 5 months with the 1-year, 2-year, and 3-year survival rates of 24.4%, 8.5%, and 4.5%, respectively. The 3-year survival for patients with jaundice was 2.9%, liver infiltration (4.2%), gallstones (0.8%), and with advanced tumor grade (1.4%). Elderly GBC patients had lower survival rates (3.8%), while the 3-year overall survival for patients residing in urban areas dropped to zero. No patients in the tumor stage (T3/T4) and with distance metastasis stage survived in 3 years, while only 1.1% of patients with advanced nodal stage survived. On receiving surgery and radiation therapy, the 3-year survival rate increased to 19.5% and 35%, respectively. The results of multivariate analysis showed that urban region (HR = 1.568, p = 0.040), gallstone or not (1.571, p = 0.049), N stage (HR = 1.468, p = 0.029), and M stage (HR = 2.289, p < 0.0001) were independent risk factors for prognosis, while surgery or not (HR = 0.573, p = 0.030) was the protective factor for the prognosis of GBC.

CONCLUSION

The overall survival of GBC in the Gangetic belt is poor. The geographical region of patients, gallstones, and N and M stage was the risk factors for prognosis, while surgery or not was the protective factor for the prognosis of GBC.

Comprehensive Analysis of the Association between Human Diseases and Water Pollutants

Drinking water is an important natural resource. For many people worldwide, especially in developing countries, access to safe drinking water is still a dream. An increasing number of human activities and industrialization have caused various physical, chemical, and biological pollutants to enter water bodies, affecting human health. Water pollutants contain a vast number of additives, such as perfluorinated chemicals, polybrominated diphenyl ethers, phthalate, nanomaterials, insecticides, microcystins, heavy metals, and pharmacologies. In this work, we aim to explore the potential relationship between water pollutants and human diseases. Here, we explored an integrative approach to identify genes, biological processes, molecular functions, and diseases linked to exposure to these water pollutants. These processes and functions affected by water pollutants are related to many diseases, including colonic neoplasms, breast neoplasms, hepatitis B, bladder cancer, and human cytomegalovirus infection. In addition, further analysis revealed the genes that play a key role in the human diseases induced by water pollutants. Therefore, conducting an integrative toxicogenomic analysis of water pollutants is more appropriate for evaluating the potential effects of water pollutants on human health.

Scientific contagion heuristic: Judgments about the acceptability of water for religious use after potential scientific treatment

We propose the concept of ‘scientific contagion’ — a mental heuristic through which any form of scientific treatment transfers some essence of ‘science’ to the processed substance, thereby affecting its nature and social acceptability. This was tested regarding the potential treatment of water from natural sources before it is used for religious purposes, as many such sources have dangerous pollutants. For an ancient natural well having a religious narrative, most participants judged that the acceptability of water would be reduced for religious purposes but not for drinking if local officials scientifically treat the water. That is not the case if religious rituals are conducted on the water instead (Study 1). If water from a “holy river” is processed scientifically, most participants predicted that it would reduce acceptability for religious use while increasing acceptability for drinking (Study 2). Potential scientific treatment without altering the composition of water from a natural spring also decreased acceptability for religious use but there was no effect on acceptability for drinking or on willingness to pay money for the water (Study 3). A follow-up study comparing acceptability for different kinds of water sources — from a holy well, natural spring, and household tap water sourced from either underground wells or rivers found lower acceptability for religious usage compared to drinking after potential scientific treatment for all these waters, but more so for holy and natural waters (Study 4). These studies establish the phenomena of scientific contagion that could have significant social implications and open future directions.

Development of function-specific indices for assessing water quality based on the proposed modifications of the expected conflicts on existing information entropy weights

Water serves numerous purposes besides drinking, such as irrigation and industrial usage. Most water quality indices developed have primarily focused on drinking water quality. However, assessing other functionalities of water bodies is also equally essential. The present study proposes a novel technique to measure water quality for two highly specific water use, i.e., assessing heavy metal contamination and irrigation suitability. The ambiguities in the current practice of entropy weights were identified, and a novel method was proposed, considering a three-dimensional approach instead of the conventional two-dimensional procedure. Weights to different parameters were assigned based on the probability estimates obtained from the frequency of observed values within acceptable limits. The proposed method's reliability, correctness, and applicability were tested using Deepor Beel's water quality dataset. Results were highly consistent with the experimental values and correlated well with other established methods. The efficacy of the method was determined by employing sensitivity analyses. Both indices showed high reliability and correctness, as no single parameter was found to be highly sensitive compared to others. Therefore, the proposed methodology proved to be the most reasonable, incorporating all the factors required for a reliable water quality monitoring program.

Cloud-based neuro-fuzzy hydro-climatic model for water quality assessment under uncertainty and sensitivity

River water quality is a function of various bio-physicochemical parameters which can be aggregated for calculating the Water Quality Index (WQI). However, it is challenging to model the nonlinearity and uncertain behavior of these parameters. When data is deficient and noisy, it creates missing and conflicting parameters within their complex inter-relationships. It is also essential to model how climatic variations and river discharge affect water quality. The present study proposes a cloud-based efficient and resourceful machine learning (ML) modeling framework using an artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS), and advanced particle swarm optimization (PSO). The framework assesses the sensitivity of five critical water quality parameters namely biochemical oxygen demand (BOD), dissolved oxygen (DO), pH, temperature, and total coliform toward WQI of the River Ganges in India. Monthly datasets of these parameters, river flow, and climate components (rainfall and temperature) for a nine-year (2011-2019) period have been used to build the models. We also propose collecting the data by placing various monitoring sensors in the river and sending the data to the cloud for analysis. This helps in continuous monitoring and analysis. Results indicate that ANN and ANFIS capture the nonlinearity in the relationship among water quality parameters with a root mean square error (RMSE) of 7.5 × 10-7 (0.002%) and 1.02 × 10-5 (0.029%), respectively, while the combined ANN-PSO model gives normalized mean square error (NMSE) of 0.0024. The study demonstrates the role of cloud-based machine learning in developing watershed protection and restoration strategies by analyzing the sensitivity of individual water quality parameters while predicting water quality under changing climate and river discharge.

Characteristics of Water Pollution and Evaluation of Water Quality in Subsidence Water Bodies in Huainan Coal Mining Areas, China

The subsidence water bodies in coal mining areas are vulnerable to being polluted by the surrounding mining production wastewater, domestic sewage, and agricultural return flow. Therefore, it is important to grasp the water quality condition of the above water bodies. A total of 16 surface water samples from 7 different subsidence water bodies in the Huainan mining area were collected and focused on the selection of 22 water quality indicators for water pollution characteristics analysis. The result of correlation analysis showed that Cr and Zn came from the same source of pollution. Three principal factors were selected by factor analysis, which could explain 82.294% of the total variance. Principal factor 1 indicated a mixture of pollution related to nitrogen and phosphorus nutrients, organic pollutants, and heavy metals; principal factor 2 showed heavy metal pollution; and principal factor 3 presented the pollution from heavy metals and cations. Results of cluster analysis showed that the water quality status of 16 sampling points could be divided into 4 clusters. The results of the heavy metal pollution index method showed that the heavy metal pollution was most serious in sample 9 (S9), S15, and S16, and the main elements of pollution were Ni, Fe, and Mn. Single-factor evaluation, comprehensive pollution index, the universal exponential formula of logarithmic power function, and membership degree method were used to evaluate the five important water quality indicators, namely total nitrogen, ammonia nitrogen, total phosphorus, dissolved oxygen, and chemical oxygen demand. The results showed that the total nitrogen pollution in the study area was more serious, most of the sites exceed class V standards of the surface water, S14 and S16 were heavily polluted. Based on the comparison of the different methods, the surface water quality in the study area can be reflected more comprehensively.

Analyses of the health status, risk assessment and recovery response of the nutritionally important catfish Clarias batrachus reared in coal mine effluent-fed pond water: a biochemical, haematological and histopathological investigation

The present field study evaluates the health status of the catfish Clarias batrachus reared in coal mine effluent (CME)-fed pond water at Rajrappa mining complex using biochemical, haematological and histopathological parameters. Simultaneously, risk assessment along with recovery response of the CME intoxicated fish following their treatment with CME-free freshwater was also studied. The CME-fed pond water fish revealed significant decrease in biomolecules concentrations and considerable increase in activities of several enzymes along with metallothionein level as compared to control. The impaired regulation of metabolic function was also revealed by blood parameters showing significant decrease in haemoglobin content (8.78 ± 0.344 g/100 mL) and red blood cells count (1.77 ± 0.12 × 106 mm3) while substantial elevation in white blood cells (187.13 ± 9.78 × 103 mm3). The histopathological study also confirmed the changes including hypertrophy of club cells of skin, swelling of secondary lamella of gills, extensive fibrosis in liver and glomerular shrinkage with increased Bowman's space in kidney. Potential health risk assessments based on estimated daily intake and target hazard quotient indicated health risks associated with the consumption of such fishes. The CME-contaminated fish when transferred to CME-free freshwater exhibited decreased metal content accompanied by eventual recovery response as evident by retrieval in biochemical and haematological parameters. Withdrawal study also revealed restoration in the activity of different marker enzymes in fish tissues including blood as well as recovery in their cellular architecture. The results of the present study validate the depuration process as an effective practice for detoxification of fish contaminated with effluent.

Water quality assessment in the ecologically stressed lower and estuarine stretches of river Ganga using multivariate statistical tool

Water quality of the Ganga River system is changing day by day due to multifold increase in population, especially near the banks of river Ganga, and associated exponential amplification of anthropogenic activities also played a remarkable role in it. The ecologically important lower and estuarine stretch of river Ganga comprising 7 different sampling stations, i.e., Jangipur, Berhampore, Balagarh, Tribeni, Godakhali, Diamond Harbour and Fraserganj, were selected for the study as the stretch is enriched with the vast number of floral and faunal diversity. The study was conducted for a period of 5 years, i.e., from 2016 to 2020. In the study, various analytical tools and techniques were used for the assessment of riverine water quality, i.e., for calculation of water quality index (WQI); The National Sanitation Foundation Water Quality Index (NSF-WQI) and the Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI) were used for the assessment. Along with WQI various statistical univariate as well as multivariate analytical tools like principal component analysis, correlation, ANOVA, and cluster analysis were also used to achieve the desired outputs. In the study, it has been observed that NSF-WQI varied from 61 to 2552, in which the higher value of NSF-WQI denoted the unsuitability of the water quality concerning the drinking water standards and vice versa. The CCME-WQI represented a similar trend as that of NSF-WQI, as it varied from 18 to 92 in which the lower value denoted degradation in the drinking water quality and vice versa. The study revealed that the Diamond Harbour-Fraserganj stretch is having an undesired level of water quality which were analyzed based on the drinking water guideline values of the Bureau of Indian Standards and that of NSF-WQI and CCME-WQI.

Novel NBN-Embedded Polymers and Their Application as Fluorescent Probes in Fe3+ and Cr3+ Detection

The isosteric replacement of C═C by B–N units in conjugated organic systems has recently attracted tremendous interest due to its desirable optical, electronic and sensory properties. Compared with BN-, NBN- and BNB-doped polycyclic aromatic hydrocarbons, NBN-embedded polymers are poised to expand the diversity and functionality of olefin polymers, but this new class of materials remain underexplored. Herein, a series of polymers with BNB-doped π-system as a pendant group were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization from NBN-containing vinyl monomers, which was prepared via intermolecular dehydration reaction between boronic acid and diamine moieties in one pot. Poly{2-(4-Vinylphenyl)-2,3-dihydro-1H-naphtho[1,8-de][1,3,2]diazaborinine} (P1), poly{N-(4-(1H-naphtho[1,8-de][1,3,2]diazaborinin-2(3H)-yl)phenyl)acrylamide} (P2) and poly{N-(4-(1H-benzo[d][1,3,2]diazaborol-2(3H)-yl)phenyl)acrylamide} (P3) were successfully synthesized. Their structure, photophysical properties and application in metal ion detection were investigated. Three polymers exhibit obvious solvatochromic fluorescence. As fluorescent sensors for the detection of Fe³⁺ and Cr³⁺, P1 and P2 show excellent selectivity and sensitivity. The limit of detection (LOD) achieved by Fe³⁺ is 7.30 nM, and the LOD achieved by Cr³⁺ is 14.69 nM, which indicates the great potential of these NBN-embedded polymers as metal fluorescence sensors.

Kinetic Studies on Delignification and Heavy Metals Uptake by Shiitake (Lentinula edodes) Mushroom Cultivated on Agro-Industrial Wastes

This study investigates the sustainable production of Shiitake (Lentinula edodes) mushroom using agro-industrial wastes. The substrate of Shiitake (80% rice straw + 20% sugar cane bagasse) was moistened with 0 (freshwater as control), 50, and 100% concentrations of secondarily treated dairy plant and sugar mill wastewaters (DPW and SMW). After proper sterilization, the cultivation was carried out under controlled environmental conditions using the bag log method for 100 days. The results revealed that DPW and SMW moistening significantly (p < 0.05) increased the nutrient levels of the formulated substrate which later gave better mushroom yield. The highest Shiitake mycelial coverage (90.70 ± 1.47 and 88.65 ± 1.82%), yield (186.00 ± 3.10 and 176.09 ± 4.12 g/kg fresh substrate), biological efficiency (80.00 ± 0.58 and 75.73 ± 0.93%), total phenol (2.84 ± 0.03 and 2.69 ± 0.03 mg/g), ascorbic acid (0.34 ± 0.03 and 0.32 ± 0.02 mg/g), and β-carotene (2.48 ± 0.06 and 2.29 ± 0.02 μg/g) contents with the minimum time taken for spawn running (60 ± 1 days) was observed using a 50% concentration treatment of both DPW and SMW, respectively. Besides this, the kinetic studies using a first-order-based model showed acceptable accuracy in predicting the rate constant for substrate delignification and heavy metal uptake by Shiitake mushroom. These findings suggest a novel approach for sustainable mushroom cultivation using agro-industrial wastes. The concept can be used for the production of high-quality mushrooms for edible and medicinal purposes while contributing toward the United Nations’ Sustainable Development Goals (SDGs 12) on responsible consumption and production of superfoods.

Assessing poverty and livelihood vulnerability of the fishing communities in the context of pollution of the Churni River, India

The present study exhibits a critical outlook on the poverty and livelihood vulnerability of the fisherman community in the context of persistent water pollution of the Churni River. The logistic regression model has identified eight factors influencing the poverty of the study area while the entropy weight method identifies the livelihood vulnerability of the fishermen. The livelihood vulnerability index of the upper stretch of the river is higher (0.65-0.67) compared to that of the lower stretch (0.46-0.57). The typical spatiality in poverty and livelihood vulnerability is triggered by the fragility of fishing livelihoods in the wake of lower concentrations of dissolved oxygen (DO), and higher BOD, COD, ammonia, nitrate and phosphate mainly due to industrial water pollution. For example, average DO ranges from 1.65 mg/l (upper stretch) to 2.50 mg/l (lower stretch) while the average BOD ranges from 5.44 mg/l (lower stretch) to 9.42 mg/l (upper stretch). This pollution induces acute ecological stress concerning declining fish diversity (from 41 to 16 fish species at the upper stretch and 41 to 23 fish species at the lower stretch during 1980-2018) as well as productivity of the existing fish species. Therefore, paralysed fishing economy and high dependency of the fishermen on the Churni River have forced them to revolve into the vicious cycle of poverty and enduring fragile livelihoods. Thus, the fishermen adopt few coping strategies like access to the nearby wetland for fishing, diversity in earning strategy and environmental movements against pollution to reduce the intensity of vulnerability. The present study would help the regional planners to frame the participatory plans for the sustainability of the riverine ecology and economy.

Oxidative, biochemical and histopathological alterations in fishes from pesticide contaminated river Ganga, India

The river Ganga basin accommodates large scale of agricultural activities, where large quantities of pesticides are applied. To assess the biological impact of pesticide residues that are continuously entering in the water body, biomarkers are common approach in bio-monitoring study as early warning signals to pollutants. In the present study qualitative and quantitative analyses of gill and liver histopathological and the biochemical parameters were determined in Rita rita and Cyprinus carpio. The difference in the histopathology and oxidative stress responses emphasize the response of selected fishes to the presence of contaminants in the water. Sloughing of lamellar epithelium and their disruption, dilated vessels, lamellar fusion, smooth muscle hypertrophy in the gill and necrosis, Vacuolation in hepatocytes, inflammation and distorted arterial walls were seen in the liver. The biochemical parameters were the main contributors to discriminate the changes in the fish physiology. In conclusion, the gill and liver histopathological responses, although not reflecting specific contaminants, but can be used as biomarkers of environmental contamination.

Elucidating competing strategic behaviors using prospect theory, system dynamics, and evolutionary game: a case of transjurisdictional water pollution problem in China

Water is a critical natural resource for socio-economic and environmental systems. In transjurisdictional river basins, when basin-wide water pollution management scheme is absent, stakeholders tend to adopt utility-maximizing behavior based on incomplete information. Such a scenario could lead to a free-riding problem. This paper attempts to elucidate the strategic behavior of riparian regions using prospect theory, evolutionary game, and system dynamics. The evolution of riparian regions' strategic behaviors is explained, and the impacts of different factors on their strategic selections are simulated. The results showed that the prospective value of factors and stakeholders' attitude to risk are a key for resolving transjurisdictional river water pollution problems. Improving the subjective judgment of the probability of water pollution, raising awareness, strengthening the penalties in "polluter pays" schemes, abandoning segmented river basin management, and building a basin-wide water management system are vital for maintaining the ecological integrity of any transjurisdictional river basin and accelerate the sustainable development of its riparian regions.

Impact assessment on water quality in the polluted stretch using a cluster analysis during pre- and COVID-19 lockdown of Tawi river basin, Jammu, North India: an environment resiliency

Pollution-free rivers give indication of a healthy ecosystem. The stretch of Tawi river particularly in the Jammu city is experiencing pollution load and the quality is degraded. The present study highlights the impact of COVID-19 lockdown on the water quality of Tawi river in Jammu, J&K Union Territory. Water quality data based upon the real-time water monitoring for four locations (Below Tawi Bridge, Bhagwati Nagar, Belicharana and Surajpur) have been obtained from the web link of Jammu and Kashmir Pollution Control Board. The important parameters used in the present study include pH, alkalinity, hardness, conductivity, BOD and COD. The river was designated fit for bathing in all the monitoring locations except Bhagwati Nagar which recorded a BOD value >5 mg/L because of domestic sewage and municipal waste dumping. The overall water quality in the river during lockdown was good and falls in Class B with pH (7.0-8.5), alkalinity (23.25-185.0 mg/L), hardness (84.25-177.5 mg/L), conductivity (117-268 ms/cm). The improved water quality obtained during lockdown is never long-lasting as evident from the BOD and COD values observed during Unlock 1.0 due to accelerated anthropogenic activities in response to overcoming the economic loss, bringing the river water quality back to the degraded state. The statistical analysis known as cluster analysis has also been performed to evaluate the homogeneity of various monitoring sites based on the physicochemical variables. The need of the hour is to address the gaps of rejuvenation strategies and work over them for effective river resiliency and for sustainable river basin management.

Heavy Metal Contamination and Human Health Implications in the Chan Thnal Reservoir, Cambodia

Chan Thnal reservoir, built during the Pol Pot period, is the major water source for the people in Krang Chek commune, Kampong Speu Province, Cambodia. Metal pollution caused by agricultural activities, improper wastewater treatment, and municipal waste disposal poses serious environmental health problems. In this study, the concentrations of four potential toxic metals (i.e., Cd, Cu, Pb, and Zn) from six locations across the reservoir were investigated both in the water and sediment. The results reflected progressive deterioration and indicated moderate to heavy pollution from the metals. The metal levels in the water were in the order of Zn > Cu > Pb > Cd. The statistical analysis revealed primary sources of heavy metals contamination in the water. Cd, Cu, Zn, and Pb in the water likely originate from anthropogenic activities including agricultural runoff (i.e., the use of fertilizers and pesticides) and urban runoff (i.e., improper wastewater discharge and waste disposal). Among the four metals, the Pb levels in the water significantly exceeded the guideline for drinking water in all locations. The health risk assessment revealed serious non-carcinogenic risks of Pb intake in the children at the age below 10 and infants. Appropriate control and protection strategies are urgently needed to cut off the main Pb exposure pathway in pregnant women, children, and infants.

Drinking water quality assessment of river Ganga in West Bengal, India through integrated statistical and GIS techniques

An attempt has been made to assess the water quality status of the lower stretch of river Ganga flowing through West Bengal for drinking using integrated techniques. For this study, 11 parameters at 10 locations from Beharampur to Diamond Harbour over nine years (2011-2019) were considered. The eastern stretch of Ganga showed a variation of Water Quality Index (WQI) from 55 to 416 and Synthetic Pollution Index (SPI) from 0.59 to 3.68 in nine years. The result was endorsed through a fair correlation between WQI and SPI (r² > 0.95). The map interpolated through GIS revealed that the entire river stretch in the year 2011, 2012, and 2019 and location near to ocean during the entire period of nine years were severely polluted (WQI > 100 or SPI > 1). Turbidity and boron concentration mainly contribute to the high scores of indices. Further, the origin of these ions was estimated through multivariate statistical techniques. It was affirmed that the origin of boron is mainly attributed to seawater influx, that of fluoride to anthropogenic sources, and other parameters originated through geogenic as well as human activities. Based on the research, a few possible water treatment mechanisms are suggested to render the water fit for drinking.

Chamoli disaster: pronounced changes in water quality and flood plains using Sentinel data

The Himalayan rivers are vulnerable to devastating flooding caused by landslides and outbreak of glacial lakes. On 7 February 2021, a deadly disaster occurred near the Rishi Ganga Hydropower Plant in the Rishi Ganga River, killing more than 100 people. During the event, a large volume of debris and broken glacial fragments flooded the Rishi Ganga River and washed away the Rishi Ganga Hydropower plant ongoing project. This study presents the impact of the Chamoli disaster on the water quality of Rishi Ganga River in upstream near Tapovan and Ganga River in downstream near Haridwar through remote sensing data. Five points have been used at different locations across the two study areas and three different indices were used such as Normalized difference water index (NDWI), Normalized difference turbidity Index (NDTI), and Normalized difference chlorophyll index (NDCI), to analyze changes in water quality. Spectral signatures and backscattering coefficients derived from Sentinel-2 Optical and Sentinel-1 Synthetic-aperture radar (SAR) data were also compared to study the changes in water quality. It was evident from the water quality indices and spectral signatures that the flood plains changed significantly. Using spectral signatures and different indices, the water level in the Chilla dam canal near Haridwar was found to decreased after the Chamoli disaster event as the flood gates were closed to stop the deposit of sediments in the canal. Results suggest changes in water quality parameters (turbidity, chlorophyll concentration, NDWI) at the five locations near the deadly site and far away at Haridwar along the Ganga River. This study is a preliminary qualitative analysis showing changes in river flood plain and water quality after the Chamoli disaster.

Integrating resilience with functional ecosystem measures: A novel paradigm for management decisions under multiple-stressor interplay in freshwater ecosystems

Moving beyond monitoring the state of water quality to understanding how the sensitive ecosystems "respond" to complex interplay of climatic and anthropogenic perturbations, and eventually the mechanisms that underpin alterations leading to transitional shifts is crucial for managing freshwater resources. The multiple disturbance dynamics-a single disturbance as opposed to multiple disturbances for recovery and other atrocities-alter aquatic ecosystem in multiple ways, yet the global models lack representation of key processes and feedbacks, impeding potential management decisions. Here, the procedure we have embarked for what is known about the biogeochemical and ecological functions in freshwaters in context of ecosystem resilience, feedbacks, stressors synergies, and compensatory dynamics, is highly relevant for process-based ecosystem models and for developing a novel paradigm toward potential management decisions. This review advocates the need for a more aggressive approach with improved understanding of changes in key ecosystem processes and mechanistic links thereof, regulating resilience and compensatory dynamics concordant with climate and anthropogenic perturbations across a wide range of spatio-temporal scales. This has relevance contexting climate change and anthropogenic pressures for developing proactive and adaptive management strategies for safeguarding freshwater resources and services they provide.

A coherent approach of Water Quality Indices and Multivariate Statistical Models to estimate the water quality and pollution source apportionment of River Ganga System in Himalayan region, Uttarakhand, India

River Ganga covers around 26% of India's land area and sustains diverse ecosystems in this overly populated area. The globally accepted coherent approach of water quality indices (WQIs) and multivariate statistical models (principal component analysis (PCA) and cluster analysis (CA)) were applied on the dataset to evaluate the spatial-temporal variation and pollution source identification and apportionment. Twenty-two hydro-chemical parameters were analyzed by collecting the samples from 20 different vertically elevated monitoring locations for different seasons. The CA evaluation of data, grouped the monitoring locations into five clusters of varied water quality with human perturbations and geo-genic inputs. The PCA analysis of an extensive dataset indicated the seven significant principal components (PCs) explaining 93.0% of the total variance and finalized 8 water quality parameters out of preselected 22 to represent good aspects of the water quality. The seasonal variation in river water quality by the Canadian Council of Ministers for Environment Water Quality Index (CCMEWQI) showed the quality class at a marginal level in summer (62.16), monsoon (59.96), and post-monsoon (60.20) season, whereas in winters (71.18), water quality was in fair condition. The response of National Sanitation Foundation Water Quality Index (NSFWQI) classified the river water in medium quality class for summer, monsoon, post-monsoon, and winter season, respectively. The present observations contribute in the usefulness of these statistical methodologies to interpret and understand large dataset and also provide reliable information to reduce the tedious and cost of water quality monitoring and assessment programs.